Toothbrush



FIG. 1 is a perspective view of my ornamental design for a toothbrush;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a side elevational view thereof, the opposite side being a mirror image;

FIG. 5 is an end view thereof as seen from the left side of FIG. 3; and,

FIG. 6 is an end view thereof as seen from the right side of FIG. 3. 

The ornamental design for a toothbrush, as shown and described. 